On 12.01.2026 16:28, Alejandro Vallejo wrote: > On Mon Jan 12, 2026 at 3:47 PM CET, Andrew Cooper wrote: >> On 12/01/2026 2:43 pm, Jan Beulich wrote: >>> On 12.01.2026 15:08, Alejandro Vallejo wrote: >>>> Debug builds stress the wrapping logic of the TLB clock by narrowing it >>>> down to 10 bits. This is inconvenient to test real time workloads on >>>> such builds. >>>> >>>> Add Kconfig option to be able to selectively use the non-stressed >>>> behaviour on debug. >>>> >>>> Signed-off-by: Alejandro Vallejo <[email protected]> >>> Hmm, yes, why not. However, ... >>> >>>> --- a/xen/arch/x86/flushtlb.c >>>> +++ b/xen/arch/x86/flushtlb.c >>>> @@ -20,11 +20,7 @@ >>>> #include <asm/spec_ctrl.h> >>>> >>>> /* Debug builds: Wrap frequently to stress-test the wrap logic. */ >>>> -#ifdef NDEBUG >>>> -#define WRAP_MASK (0xFFFFFFFFU) >>>> -#else >>>> -#define WRAP_MASK (0x000003FFU) >>>> -#endif >>>> +#define WRAP_MASK (IS_ENABLED(CONFIG_DEBUG_TLB_CLK) ? 0x3FFU : UINT32_MAX) >>> ... the comment then will want updating as well, I'd say. It doesn't go >>> terribly stale this way, but at least slightly. I'd suggest to minimally >>> drop "builds". > > I left the comment because the rationale still holds. Dropping "builds" sounds > good to me. > >> >> I'm suggest just dropping WRAP_MASK. >> >> We've done this locally in the XenServer patchqueue since 2011 or so due >> to the overhead, and I don't think it's interesting enough to warrant a >> separate option. >> >> ~Andrew > > I don't mind much either way. I need it gone for my needs and I don't care > much > how it happens. > > Jan + Roger, do you have strong opinions on the matter?
Dropping altogether is fine with me. Jan
